Field
Exemplary embodiments relate to a display device including a touch sensor.
Discussion of the Background
A flat panel display (FPD) such as an organic light emitting diode display (OLED), a liquid crystal display (LCD), and an electrophoretic display (EPD) includes a display panel in which a field generating electrode and an electro-optical active layer are formed. For the electro-optical active layer, the OLED includes an organic emission layer, the LCD includes a liquid crystal layer, and the EPD includes charged particles. The field generating electrode is connected to a switching element, such as a thin film transistor, to receive a data signal, and the electro-optical active layer converts the data signal into an optical signal to display an image.
The display device may include a touch sensing function, with which a user can interact, in addition to a function of displaying the image by the display panel. The touch sensing function is to determine touch information, such as whether an object touches the screen and the touch position thereof, by sensing a change in pressure, charge, light, and the like which are applied onto the screen in the display device, when the user touches the screen with a finger or a touch pen. The display device may also receive an image signal based on the touch information.
The touch sensing function may be implemented by a capacitive touch sensor including touch electrodes. In the capacitive touch sensor, touch electrodes form a capacitor and sense a change in the capacitance of the capacitor which is altered by a touch. The touch information may be generated based on the change in capacitance. However, due to the parasitic capacitance generated between the touch electrode and the electrode of the display panel, sensitivity of the sensor may deteriorate. Parasitic capacitance also becomes a problem as the distance between the touch electrode and the electrode in the display panel is decreased.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.